I'm in middle school too and I could help u but I have absolutely no idea what you are asking.
Answer:
A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly
12 grams of carbon-12 (i.e., 6.023 X 1023).
Explanation:
C is the correct answer because density is mass per unit volume and when you divide it we that volume is greater than mass so density is less density density is directly proportional to Mass Density is inversely proportional to volume
Solution :
A cell that is concentrated is constructed by the same half reaction for the anode as well as he cathode.
We know,
In a standard cell,
the reduction half cell reaction is :

The oxidation half ell reaction :

Thus the complete reaction of the cell is :

cell = 
Answer:
Option F. 3moles
Explanation:
The equation for the reaction is given below:
2H2 + O2 —> 2H2O
from the equation,
2moles of H2 required 1mole of O2.
Therefore, 6moles of H2 will require = 6/2 = 3moles of O2